A prior art capsule assembly 10 is depicted in FIG. 1. The capsule assembly 10 includes a slip ring 12, a pair of semi-circular brush blocks 14 and a cylindrical housing 16. The capsule assembly 10 is formed by placing the pair of brush blocks 14 around the slip ring 12 and then the assembly of the brush blocks 14 and the slip ring 12 are placed within the housing 16.
The slip ring 12 has a body formed from two separate members including a ring and lead member 18 (rings 24 and leads 34) joined to a backshaft member 20. The slip ring 12 includes an elongated cylindrical ring portion. Positioning the ring members 18 are radially extending portions 26 made of an electrically non-conductive material which separate the electrically conductive rings 24. Each of the brush blocks 14 has a plurality of brushes 28 which are each in mechanical contact with a corresponding ring 24. A front bearing 30 is mounted on the slip ring member 12 and a backshaft bearing 32 is mounted to the backshaft member 20.
The backshaft member 20 extends outwardly from the housing 16. The backshaft member 20 is grasped and rotated by another component (not shown). The slip ring 12 rotates within the brush blocks 14 and the brushes 28 from brush blocks 14 contact the rings 24 on slip ring 12 so that signals to/from the rotating slip ring 12 can be communicated to/from stationary brush blocks 14 in a known manner.
As depicted in FIGS. 1 and 2, the backshaft bearing 32 has one side thereof in contact with a front flange 36 formed on backshaft member 20. The opposite side of backshaft bearing 32 is retained by a standard retainer such as a retaining clip 38 or the like. The retaining clip 38 has its inner periphery positioned in a groove (not shown) on back shaft member 20 and depending on manufacturing tolerances, the backshaft bearing 32 may not be fully restrained in an axial (longitudinal) direction or may be too tightly retained resulting in stress on the bearing. The disadvantage is that there is some play allowing the back shaft bearing 32 to move back and forth in an axial direction.
Further, the backshaft member 20 and ring member 18 must not rotate relative to each other. The backshaft member 20 and the ring member each have mating hexagonal portions. As depicted in FIG. 3, backshaft member 20 has a female hexagonal portion 42 which mates with a male hexagonal portion 40 on ring member 18. The disadvantage is that this two piece construction is time consuming and expensive because two parts must be injection molded. An additional disadvantage is that the wires 34 must be potted to seal the wires 34 to the backshaft member 20 resulting in additional cost.